Stock stop for automatic lathes



'F iled Jan. 22, 1947 g- 5, 1952 4 G. E. cuT'rAT 2,605,539

. STOCK STOP FOR AUTOMATIC LATHES 3 Sheets-Sheet 1 v G. E. CUTTAT swocxSTOP FOR AUTOMATIC LATHES Aug. 5, 1952 S'Sheets-Sheet 2 Filed Jan. 22,1947 v I STOCK STOP FOR AUTOMATIC LATHES Filed J n.'22,j1947 i *5 sSheets-Sheet-3 the length of-feedof the work,

Patented Aug. 5, 1952 f-2,e05,5-s-9= v lSTOCK STOP FOR AUTOMATICLATHESGeneva-,; Switzerland, asre De Machines Du Hau'tlthin, Ham-Elfin,Francega compamyof France Ap lication January 22,l|l47,1SerialNoT.723,596

In France November 23,1945

Georges Emile Cuttat, signor to Manufactu The present invention concernsthe oscillatin thrust blocksusedin automatic lathes tolimit and,particularly, of the work bar. At the presenttime, these-oscillatingthrust blocks are capable only of a rotary motion about their axle, in aplane perpendicular to the bar. This arrangement is not without itsdrawbacks as the friction exerted by the end of the bar on the thrustblock, (the bar bein clamped in the headstock), offers a resistancewhich may be fairly considerable, to the motion of the thrust block.

In order to eliminate this drawback, an object of the present inventionis an oscillatory thrustblock device receiving automatically from itscontrolling organ a slight longitudinal motion parallel to the bar,before the controlling organ imparts to the thrustblock its oscillatingmotion perpendicular to the bar.

One type of embodiment of an oscillating thrustblock device, inaccordance with the invention will be described, hereinafter, by way ofexample and is represented on the appended drawings in which:

Figure 1 is a side elevation of the whole device; Figure 2 is anelevation at 90 to that of Figure Figure 3 is a modification of Figure 2for the case where the drive is efiected by the main cam shaft insteadof being eifected by the auxiliary shaft;

Figure 4 is a cross section, on an enlarged scale, of Figure l; and

Figures 5 to 9 are schematics, at 90 to Figure 4, showing thecooperation of the thrust block organ of the control lever with thestops of the thrust block ring.

It will be seen from Figure 1 that, to determine the extension of thework bar from headstock 2, an oscillating thrust block 3 is used,mounted on an axle 4 capable of turning inside a fixed part 6 of theframe (see also Figure 2). When bar I has been pushed against thrustblock 3, and firmly clamped, the friction exerted between the bar andthe thrust block opposes fairly strongly the motion of the latter torelease the end of the bar. According to the present invention, it isproposed to eliminate this friction.

To this effect, (Figure 4), the axle 4 of the oscillating thrust blockoffers, at its rear end, a threaded part 1 on which is screwed the endof the controlling organ, either lever B, articulated to link 9, itselfarticulated to bell-crank lever connected through link l2 to a lever l3capable of oscillating about an axle l4, and carrying a r ller zfilazims. (01. 29-58) I 2-,"onauxiliary shaft l6.

2 engaged by-a cam [5, locked, in the case of Figure The drive can beeffected, asshow-n on Figure 3, in a 7 does not have to be describedespecially, from the main cam shaft [1.

A return spring I8 connects bell crank lever l l to a fixed point offrame 6.

The axle 4 of the oscillating thrust block is associated, in rotation,by two fingers IS, with a ring 2|, constantly urged towards the left ofFigure 4, by a spring washer 22 bearing against a lid 23 attached toframe 6. Ring 2| carries two stops (Figure 5), 24, 25 between which athrust block organ 26 is engaged, associated with control lever 8. Aspring 21 connects one point of control lever 8 to one of the steps '25of ring 2|.

The operation of the device is as follows:

Suppose that we start from the position in which oscillating thrustblock 3 is in contact with bar I. The roller of lever l3 moves on caml5, which, through lever l and link 9 rotates control lever 8 whilestretching return spring I8. Then,

' axle 4 of the oscillating thrust block is prevented from turning bythe friction of thrust block 3 on bar I. The result is that controllever B is slightly unscrewed on threaded part 1 of axle 4. But spring22, exerting its action through ring 2| pushes axle 4 towards the leftuntil lever 8 bears against a shoulder of frame 6, (position representedon Figure 4). Meanwhile, thrust block organ 25 (Figures 5 and 6) hasturned freely until contacting stop 25 .of ring 2!, (position shown onFigure 6). From that time on, control lever 8, continuing its rotation,drives stop 25 and, consequently ring 2|; the latter, inturn, rotatesaxle 4 and thrust block 3 rises, releasing bar The position of Figure 7is then reached which corresponds to the position of the apex of cam l5.When this apex has been passed, it is return spring l8, which, uponextending, will cause the oscillating thrust block to move down, thendisplace it towards the right, so that the new bar introduced in theheadstock can be applied against it. Lever 8 rises, (Figure 8)accompanied in its motion by stop 25, owing to the pull of spring I8,axle 4 therefore rotates, causing oscillating thrust block 3 to movedown. Stop 24 then bears against frame 6. Then ring 2| is no longerdriven and lever 8, continuing its upward motion, screws on threadedpart 1, with the result of displacing axle 4 towards the right, (Figure9) until it is in the required position. Bar I can then be pushedagainst oscillating thrust block 3 without any risk of the oscillatingthrust block moving.

manner which What I claim is:

1. In a stock stop for an automatic lathe, an axle parallel to thedirection of feed and rotatably and slidably mounted in a fixed part ofthe lathe, a stop mounted eccentrically on said axle, said axle having athreaded part, elastic means interposed between said axle and the fixedpart of the lathe for moving said axle in the direction of feed, aninternally threaded oscillating member mounted in the fixed part of thelathe, engaging the threaded part of said axle for imparting to saidaxle a first longitudinal limited releasing movement under the action ofsaid elasticmeans when the rotation of said axle is prevented by thefriction of the stock on the stop, and means provided on saidoscillating control member adapted to actuate means associated with saidaxle to impart to said axle a rotating movement after the firstlongitudinal movement.

2. In a stock stop for an automatic lathe, an axle parallel to thedirection of feed and rotatably and slidably mounted in a fixed part ofthe lathe, a stop mounted eccentrically on said axle, said axle having athreaded part, an internally threaded oscillating member mounted in thefixed part of the lathe concentrically with the axle at the rear of saidaxle and threadably connected therewith, a ring connected to said axleelastic means interposed between the fixed part of the lathe and saidring for moving said ring in the direction of the feed, two stopsprovided on the periphery of said ring, a stop provided on saidoscillating control member between said two stops of the ring, andelastic means connecting one of the two stops of said ring with saidoscillating control member.

'. GEORGES EMILE CUTTAT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Stull June 17, 1941

